How-To: Text Sliding out of a Circle 2D
Here is a quick method for that:


Create a circle curve object.
Enter Edit Mode, make sure all points are selected, then V to switch handle type to Aligned.
AltC to make it an open curve (acyclic).
Select the tip point, then E to extrude it. Note that the length should no less than the length of the text.
You can manually tweak the shape by extruding and transforming points to make it a circle (or several circles for a longer rolling later).
Add a Follow Curve modifier to the text object, and choose the curve as path object. You may also want to scale the text to match the curve.
If the text appears flipped, you can select the path then enter Edit Mode, then W > Switch Direction. 
Then move the text horizontally to the expected location.




Finally, you can key the movement for path object to get the result:



Example File: